https://www.youtube.com/watch?feature=youtu.be&v=_6hNIWB-IoU&app=desktop
Hi Hiro
You have come a long way since you uploaded this video, but your right knee still drops away front the contact with your front knee and tends to hangout and pull your forward in your offside turn from time to time. You can see from this video that you are trailing your right hip and most of the support is in your rear right foot with around 70% of your weight in the rear foot. Leg and tail of your ski.
Once we get you riding the center of your ski more and on the neutral line, you will feel the huge improvement in balance, efficiency and control not only across the wakes, but in your turns and all aspects of your skiing.